Go 7007 FAQ

Note: This is page is based on content from the defunct oss.wischip.org website.

Open Source Software FAQ

  1. GO7007 Hardware Questions
  2. GO7007 Linux Driver Questions

GO7007 Hardware Questions

What video formats does the GO7007 support?

The GO7007 can deliver video in MPEG1, MPEG2, MPEG4, H.263+ or MJPEG. H.263+ is not yet supported with the open-source Linux driver. USB-based devices are unable to deliver raw video.

What audio formats does the GO7007 support?

The GO7007 always delivers audio as uncompressed PCM. If audio compression is necessary it must be performed by the host CPU.

Does the GO7007 support DivX compression?

DivX files are AVI files that conform to a specific set of rules. In general, DivX files must contain MPEG4 video and MP3 audio. The GO7007 can produce MPEG4 video that is suitable for packaging into a DivX file, but all remaining processing to create the DivX file must be performed by software on the host CPU. Some vendors, including Plextor, provide software that produces valid DivX files, but Micronas USA does not have a public DivX software offering.

Can the GO7007 be upgraded to support new compression formats?

No. The firmware in the GO7007 may be updated to tweak the input filters, deinterlacing mechanism, or bitrate control, but the performance levels the hardware is able to support require that the chip be hard-wired for the specific supported formats.

Is there a retail product based on the GO7007 that connects to a PCI slot instead of the USB?

Plextor offers the PX-TV432P, but only in the Japanese market currently.

Linux Driver Questions

How do I install the driver?

You will need to download the tar file containing the driver source code and follow the instructions in the README to compile the driver against your kernel 2.6 source code tree.

Do you supply binary packages (.rpm, .deb, etc)?

Because of the wide range of kernel configurations possible even within a single Linux distribution, we are unable to supply precompiled binary packages.

Can the GO7007 Linux driver be shipped as part of a Linux distribution?

Most likely, yes. Please see the license information included in the README and other files in the driver archive.

What software is compatible with the GO7007 Linux driver?

Unfortunately, there are very few applications compatible with the GO7007 Linux driver. USB-based devices do not support raw (uncompressed) video modes or overlay which many applications require to provide a "preview" window of the video signal. In addition, the base V4L2 specification does not provide a full range of controls for MPEG hardware encoders such as the GO7007, so Micronas USA has defined several proprietary V4L2 extensions for controlling the encoder. These extensions, documented in the README file in the driver distribution, must be supported in the application to configure the GO7007 before encoding.

The GO7007 Linux driver archive contains an example application called `gorecord` that can be used to test the driver and hardware. A list of third-party Linux applications known to support the GO7007 driver can be found on the front page.

Why doesn't gorecord support feature <foo>?

The gorecord application is intended only to be an example program used for testing features of the driver and hardware. Because the code is intended to be simple to understand and re-use, it only contains features specific to the operation of the GO7007 driver. Features implemented only in software, such as audio encoding, will not be added to gorecord.

However, if you would like to implement new features in gorecord yourself, you are welcome to use the gorecord code as the basis for your own open-source or proprietary application. Please see the license in the comments at the start of the gorecord source files for more information.

Why do files with gorecord lose audio-video synch after some time?

As with all video capture devices, the audio and video sampling clocks on the GO7007 are not perfectly synchronized, so several minutes into a recording there will be a noticable drift between the audio and video tracks. There is no A/V synch correction in gorecord for the reasons outlined above.

Why does gorecord stop capturing after 40 minutes?

Using the default gorecord parameters, recording for about 40 minutes will produce an AVI file of around 1GB in size. Many programs that use the AVI format are unable to read files larger than 1GB, so gorecord will refuse to create files larger than this.